U.S. patent number 8,622,792 [Application Number 13/684,959] was granted by the patent office on 2014-01-07 for rack and pinion sieve adjustment mechanism.
This patent grant is currently assigned to CNH America LLC. The grantee listed for this patent is CNH America LLC. Invention is credited to Craig Elwyn Murray.
United States Patent |
8,622,792 |
Murray |
January 7, 2014 |
Rack and pinion sieve adjustment mechanism
Abstract
A sieve adjustment mechanism including a rack gear, a pivot
handle, and an actuator, to mitigate lost motion/play in pivot link
sieve assembly. The rack gear is movable between a first and a
second position and connectable to a first sieve segment for moving
the first sieve segment between a first sieve position and a second
sieve position. The pivot handle includes a pinion gear at a first
end of the pivot handle for operatively engaging the rack gear for
moving the rack gear between the first and second positions and a
second end opposite the first end. The pinion gear is rotatable
about a first axis. The actuator is connected to the second end of
the pivot handle for pivoting the pivot handle about the first axis
to move the rack gear between the first and second positions.
Inventors: |
Murray; Craig Elwyn (Davenport,
IA) |
Applicant: |
Name |
City |
State |
Country |
Type |
CNH America LLC |
New Holland |
PA |
US |
|
|
Assignee: |
CNH America LLC (New Holland,
PA)
|
Family
ID: |
49726898 |
Appl.
No.: |
13/684,959 |
Filed: |
November 26, 2012 |
Current U.S.
Class: |
460/101 |
Current CPC
Class: |
B07B
1/4636 (20130101); A01F 12/448 (20130101) |
Current International
Class: |
A01F
12/32 (20060101); B07B 1/00 (20060101) |
Field of
Search: |
;460/101,8,6,42,109,5
;209/394 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
19824462 |
|
Dec 1999 |
|
DE |
|
4183321 |
|
Jun 1992 |
|
JP |
|
Primary Examiner: Fabian-Kovacs; rpad
Attorney, Agent or Firm: Sheldrake; Patrick M. Sharifi;
Seyed V.
Claims
I claim:
1. A sieve adjustment mechanism comprising: a rack gear movable
between a first and a second position and connectable to a sieve
segment of a sieve for a sliding movement of the sieve segment in a
plane thereof between a first sieve position and a second sieve
position, the sliding movement in the plane of the sieve for an
adjustment of a sieve size; a pivot handle having a pinion gear at
a first end of the pivot handle for operatively engaging the rack
gear for moving the rack gear between the first and second
positions and a second end opposite the first end, wherein the
pinion gear is rotatable about a first axis; and an actuator
connected to the second end for pivoting the pivot handle about the
first axis to move the rack gear between the first and second
positions, actuation of the actuator induces a force along a single
direction on the rack gear via a pivot, the single direction
mitigates a lost motion in the pivot during the adjustment of the
sieve size, the single direction parallel to a length of the rack
gear.
2. The sieve adjustment mechanism of claim 1, wherein the pinion
gear is integrally formed with the pivot handle.
3. The sieve adjustment mechanism of claim 1, wherein the pinion
gear includes gears circumscribing about 1/3 to about 2/3 of a
circumference of the pinion gear.
4. The sieve adjustment mechanism of claim 1, wherein the actuator
is pivotally connected to the second end of the pivot handle.
5. The sieve adjustment mechanism of claim 1, wherein the actuator
is operatively in communication with a controller.
6. A cleaning system for an agricultural combine comprising: a
sieve that includes a first sieve segment disposed adjacent a
second sieve segment; and a sieve adjustment mechanism operatively
connected to at least one of the first and second sieve segments
for moving at least one of the first and second sieve segments
relative to the other to adjust the size of a sieve opening of the
sieve, the sieve adjustment mechanism including a rack and pinion
gear mechanism for linearly moving at least one of the first and
second sieve segments relative to the other, wherein the rack and
pinion gear mechanism includes a pinion gear integrally formed with
an elongated handle; and a pivot assembly operatively connected to
the pinion gear mechanism for translation of a rotation induced on
the pivot assembly to a force, the force operates in a single
direction on the rack, the single direction mitigates a play of the
pivot assembly during an adjustment of the sieve size via a sliding
movement in a plane of the sieve, the single direction parallel to
a length of the rack.
7. The cleaning system of claim 6, wherein the pinion gear includes
a first end for operatively engaging a rack gear for moving the
rack gear between first and second positions and a second end
opposite the first end, and wherein the pinion gear pivots about a
first axis.
8. The cleaning system of claim 6, wherein the sieve adjustment
mechanism further includes an actuator connected to the rack and
pinion gear mechanism for pivoting the pinion gear about a first
axis.
9. The cleaning system of claim 8, wherein the actuator is
pivotally connected to the rack and pinion gear mechanism.
10. The cleaning system of claim 8, wherein the actuator is
operatively in communication with a controller.
11. The cleaning system of claim 6, wherein at least one of the
first and second sieve segments is connected to a rack gear of the
rack and pinion gear mechanism.
12. The cleaning system of claim 11, wherein linear translation of
the rack gear moves at least one of the first and second sieve
segments relative to the other to adjust the size of a sieve
opening of the sieve.
13. The cleaning system of claim 6, wherein the pinion gear
includes gears circumscribing about 1/3 to about 2/3 of a
circumference of the pinion gear.
14. The cleaning system of claim 6, wherein the pinion gear
includes gears circumscribing about 1/2 of a circumference of the
pinion gear.
15. A sieve assembly comprising: a sieve that includes a first
sieve segment disposed adjacent a second sieve segment; an arm
extending between and operatively connecting the first and second
sieve segments, the arm including a rack gear integrally formed at
an end of the arm; a sieve adjustment mechanism operatively
connected to the arm for moving at least one of the first and
second sieve segments relative to the other to adjust the size of a
sieve opening of the sieve via a sliding motion in a plane thereof,
the sieve adjustment mechanism including a pinion gear operatively
engaged with the rack gear for moving the arm in a linear
direction; and an actuator that induces a force along a single
direction on the rack gear via a pivot, the single direction
mitigates a lost motion in the pivot during an adjustment by the
sieve adjustment mechanism, the single direction parallel to a
length of the rack gear.
16. The sieve assembly of claim 15, wherein the pinion gear
includes an integrally formed elongated handle.
17. The sieve assembly of claim 15, wherein the actuator is
connected to the pinion gear for pivoting the pinion gear about a
first axis.
18. The sieve assembly of claim 17, wherein the actuator is
operatively in communication with a controller.
19. The sieve assembly of claim 17, wherein the actuator is
configured to move in a direction substantially transverse to the
linear direction.
20. The sieve assembly of claim 15, wherein the pinion gear
includes gears circumscribing about 1/3 to about 2/3 of a
circumference of the pinion gear.
Description
BACKGROUND OF THE INVENTION
The present invention generally relates to a sieve adjust mechanism
and more particularly to a rack and pinion sieve adjustment
mechanism applicable to agricultural combines.
In an agricultural harvester combine, the grain is harvested,
threshed and cleaned. In conventional agricultural combines, the
stocks of grain flow on a conveyer from the harvester to a
threshing drum where the grain is loosened from the stock. The
grain is then cleaned by passing it through a cleaning
assembly.
In most combines, the cleaning assembly contains three main
components: a blower, an upper sieve and a lower sieve. The blower
has its own housing, whereas the upper sieve and lower sieve are
mounted on a cleaning shoe. The sieve consists of a large number of
louvers or slats which, based on the crop conditions, need to be
opened or closed to control the separating characteristics. Grain
is cleaned and separated by passing the grain through the sieves of
the cleaning assembly.
FIG. 1 illustrates a conventional sieve adjustment mechanism 100
used in the industry consisting of pivoting handles or lever arms
102 which push or pull the louvers or slats through arm 104 to
adjust the size of the sieve opening. However, a problem associated
with conventional sieve adjustment mechanisms is that there is
generally a significant amount of lost motion or play in the pivot
joints of handle 102 and arm 104. The lost motion of conventional
sieve adjustments arises from the mechanisms used to adjust the
positioning of sieve slats or louvers. Such conventional sieve
adjustment mechanisms rely on linkages rotating about fixed pivot
points, e.g., 106, as a result there is not a true translation in a
single direction of motion so the slats or louvers open or close at
different rates during a range of motion of the handles 102. As a
result, when a sieve is remotely adjusted using e.g., in-cab
electronics, this lost motion/play cannot be easily accounted for
and results in less than optimal slat openings or slat openings
differing from that set or anticipated by the user.
Thus, there is a need for a system and apparatus for a sieve
adjustment mechanism that addresses the aforementioned deficiencies
of conventional sieve adjustment mechanisms. Such needs are met by
the sieve adjustment mechanism of the present invention.
BRIEF SUMMARY OF THE INVENTION
In accordance with a first aspect, the present invention provides a
sieve adjustment mechanism that includes a rack gear, a pivot
handle and an actuator. The rack gear is movable between a first
and a second position and connectable to a sieve segment of a sieve
for moving the sieve segment between a first sieve position and a
second sieve position. The pivot handle includes a pinion gear at a
first end of the pivot handle for operatively engaging the rack
gear for moving the rack gear between the first and second
positions and a second end opposite the first end. The pinion gear
is rotatable about a first axis. The actuator is connected to the
second end of the pivot handle for pivoting the pivot handle about
the first axis to move the rack gear between the first and second
positions.
In accordance with a second aspect, the present invention provides
a cleaning system for an agricultural combine that includes a sieve
and a sieve adjustment mechanism. The sieve includes a first sieve
segment disposed adjacent a second sieve segment in an end to end
relation. The sieve adjustment mechanism is operatively connected
to at least one of the first and second sieve segments for moving
at least one of the first and second sieve segments relative to the
other to adjust the size of a sieve opening of the sieve. The sieve
adjustment mechanism includes a rack and pinion gear mechanism for
linearly moving at least one of the first and second sieve segments
relative to the other. The rack and pinion gear mechanism includes
a pinion gear integrally formed with an elongated handle.
In accordance with a third aspect, the present invention provides a
sieve assembly that includes a sieve, an arm and a sieve adjustment
mechanism. The sieve includes a first sieve segment disposed
adjacent a second sieve segment. The arm extends between and is
operatively connected to the first and second sieve segments. The
arm includes a rack gear integrally formed at an end of the arm.
The sieve adjustment mechanism is operatively connected to the arm
for moving at least one of the first and second sieve segments
relative to the other to adjust the size of a sieve opening of the
sieve. The sieve adjustment mechanism includes a pinion gear
operatively engaged with the rack gear for moving the arm in a
linear direction.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing summary, as well as the following detailed
description of the invention, will be better understood when read
in conjunction with the appended drawings. For the purpose of
illustrating the invention, there are shown in the drawings
embodiments which are presently preferred. It should be understood,
however, that the present invention is not limited to the precise
arrangements and instrumentalities shown.
In the drawings:
FIG. 1 is a bottom perspective view of a conventional sieve and
sieve adjustment mechanism for an agricultural combine;
FIG. 2 is a top perspective view of the conventional sieve and
sieve adjustment mechanism of FIG. 1;
FIG. 3 is an exploded perspective view of a sieve adjustment
mechanism in accordance with a preferred embodiment of the present
invention;
FIG. 4 is a perspective view of the sieve adjustment mechanism of
FIG. 3 in a first position;
FIG. 5 is a perspective view of the sieve adjustment mechanism of
FIG. 3 in a second position;
FIG. 6 is an elevation view of the sieve adjustment mechanism of
FIG. 3 assembled to a sieve;
FIG. 7 is a schematic diagram of the sieve adjustment mechanism of
the present invention;
FIG. 8 is a top perspective view of the sieve adjustment mechanism
of FIG. 3 assembled to a sieve;
FIG. 9 is an enlarged partial side elevation view of the sieve
adjustment mechanism of FIG. 2; and
FIG. 10 is an elevation view of a sieve adjustment mechanism in
accordance with another aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the preferred embodiments
of the invention illustrated in the accompanying drawings. Wherever
possible, the same or like reference numbers will be used
throughout the drawings to refer to the same or the like features.
It should be noted that the drawings are in simplified form and are
not drawn to precise scale. In reference to the disclosure herein,
for proposes of convenience and clarity only, directional terms
such as top, bottom, above, below, and diagonal, are used with
respect to the accompanying drawings. Such directional terms used
in conjunction with the following description of the drawings
should not be construed to limit the scope of the invention in any
manner not explicitly set forth. Additionally, the term "a," as
used in the specification, means "at least one." The terminology
includes the words above specifically mentioned, derivatives
thereof, and words of similar import.
The terms "grain," "tailing," and "crop material" are used
throughout the specification for convenience and it should be
understood that these terms are not intended to be limiting. Thus,
"grain" refers to that part of a crop which is harvested and
separated from discardable portions of crop material.
Referring to FIGS. 3-9, in accordance with a preferred embodiment,
the present invention provides a sieve adjustment mechanism 10 for
a sieve 108, such as a sieve for an agricultural combine cleaning
system (FIG. 2). The sieve adjustment mechanism 10 includes a rack
gear 12, a pivot handle 14 and an actuator 160. Collectively, the
rack gear 12 and pivot handle 14 is also referred to as a rack and
pinion gear mechanism. The sieve 108 can e.g., be a sieve as used
in an agricultural combine that includes a first sieve segment 110
disposed adjacent to a second sieve segment 112 in an end to end
relation along a first axis A. As used herein, the term "sieve
segment" refers to a slat or louver, or a plurality of slats or
louvers connected together. Each slat is composed of a plurality of
parallel, longitudinally spaced upward and downwardly inclined
fingers. The fingers of adjacent ones of the slats defining sieve
openings therebetween for the passage of crop material of a desired
maximum size therethrough, i.e., clean grain. Slats are
simultaneously pivotable about respective pivotal axes through a
range of pivotable positions for varying the opening size of the
sieve in the well known conventional manner. Alternatively, the
slats can be moved in a linear direction to vary the opening size
of the sieve. Further details regarding the structure and operation
of conventional slats and louvers of sieves applicable to the
present invention are disclosed in U.S. Pat. No. 7,371,162, the
entire disclosure of which is hereby incorporated by reference
herein.
The rack gear 12 is movable between a first position (FIG. 4) and a
second position (FIG. 5). Referring to FIG. 6, the rack gear 12 is
directly connected to one of the first or second sieve segments
110, 112 for moving one of the first and second sieve segments 110,
112 relative to the other to adjust the size of a sieve opening of
the sieve 108. The rack gear 12 is directly connected to one of the
first or second sieve segments 110, 112 via arm 104. The arm 104
extends along a length of the sieve 108 in a direction
substantially parallel to axis A and connects to each sieve segment
of the sieve 108 for pivotably (or translationally) moving the
sieve segments.
For purposes of convenience only, the present embodiment will
hereinafter be described with the rack gear 12 being connected to
the first sieve segment or slat 110 of the sieve 108. In
particular, the rack gear 12 is rigidly connected to the first
sieve segment 110 or arm 104 without any pivot joints. As such, the
rack gear 12 provides direct translational motion to the first
sieve segment 110 without any lost motion due to variances inherent
in pivot joints or linkage systems.
In the first position, the first sieve segment 110 is at a first
position that e.g., represents a smallest size opening for the
sieve 108. In the second position, the first sieve segment 110 is
at a second position that e.g., represents a largest size opening
for the sieve 108. However, the rack gear 12 is configured to be
movable and positionable throughout a range of motion corresponding
to a range or plurality of positions and consequently a plurality
of sieve size openings.
The rack gear 12 is configured as a linear gear bar, as best shown
in FIG. 3, and includes teeth 16. The teeth 16 are configured to
operatively engage the pivot handle 14. The rack gear 12 has a
first end 12a and a second end 12b that is opposite the first end
12a. About the second end 12b is a through hole 18 used for
connecting the rack gear 12 to the first sieve segment 112 or arm
104. The through hole 18 preferably extends in a direction
perpendicular to a longitudinal axis of the rack gear 12. The
overall longitudinal length of the rack gear 12 is sized
sufficiently to translate the first sieve segment 110 through a
range of motion relative to a second sieve segment 112 in order to
provide the necessary or desired size opening for the sieve
108.
The pivot handle 14 is configured, as best shown in FIG. 3. The
pivot handle 14 is an elongated handle that includes a pinion gear
20 attached to a first end 14a of the pivot handle 14. Preferably,
the pinion gear 20 is integrally formed with the pivot handle 14.
The pinion gear 20 is also preferably configured as a partial
pinion gear. That is, the pinion gear 20 includes teeth 22 covering
about 1/3 to about 2/3 of a circumference of the pinion gear 20.
More preferably, the teeth 22 cover about 1/2 of a circumference of
the pinion gear 20. The teeth 22 are configured to correspondingly
engage teeth 16 on the rack gear 12. A central through hole 26
extends through the pinion gear 20 in a direction coaxial with a
central longitudinal axis B of the pinion gear 20. The central
through hole 26 is sized to receive a pivot axis 28 that extends
therethrough for pivotably mounting the pivot handle 24 on a
support 30, as further described below.
In sum, the pinion gear includes a first end for operatively
engaging a rack gear for moving the rack gear between first and
second positions and a second end opposite the first end. Thus, in
operation, the pinion gear 20 pivots about axis B which is coaxial
with the central through hole 26.
A handle 24 of the pivot handle 14 extends from the pinion gear 20,
as shown in FIG. 3. In other words, the handle 24 extends from the
pinion gear 20 in a direction transverse to the central
longitudinal axis B of the pinion gear 20.
About a second end 14b of the pivot handle 14, which is opposite
the first end 14a, is a "U" shaped bracket 32. The bracket 32
includes a through hole 34 that extends through both ends of the
"U" shaped bracket 32. The "U" shaped bracket 32 pivotably connects
the pivot handle 14 to the actuator 160, as shown in FIG. 6.
The actuator 160 can be any actuator known in the art, such as a
hydraulic actuator, and electric actuator and the like. The
actuator 160 is operatively connected to and in communication with
a controller 36 (FIG. 7). The controller 36 can be any computer,
logic control system, or the like, including the onboard controls
of e.g., an agricultural combine. The actuator 160 is mounted to
the sieve 108 and connected to the second end 14b of the pivot
handle 14 to pivot the pivot handle 14 about the pivot axis 28. In
other words, the pivot handle 14 pivots about the axis B.
FIGS. 4 and 5 illustrate the sieve adjustment mechanism 10
assembled to the support 30. The support 30 is configured, as best
shown in FIGS. 3-5, and includes a mounting bracket end 36 for
mounting to the sieve 108, as shown in FIG. 8. The mounting bracket
end 36 includes an aperture 38 (FIG. 6) sized to allow for the
passage of the rack gear 12 therethrough.
Opposite the mounting bracket end 36 is a sieve adjustment
mechanism mounting end 40 which the sieve adjust mechanism 10
mounts to. The sieve adjustment mechanism mounting end 40 is
configured as a track 42 that extends in a direction towards the
first sieve segment 110 or arm 104 when the support 30 is mounted
to the sieve 108. Preferably, the track 42 extends in a direction
substantially parallel to longitudinal axis A.
The track 42 includes opposing side walls 44a, 44b and a lateral
wall 44c. The lateral wall 44c serves as a guiding surface about
which a surface of the rack gear 12, opposite the surface of the
rack gear 12 that includes teeth 16, slidingly engages. The
opposing side walls 44a, 44b include a through hole 46 that extends
through both side walls 44a, 44b and which is configured to receive
the pivot axis 28. The through hole 46 is spaced from the lateral
wall 44c a distance such that the pinion gear 20 operatively
engages the rack gear 16 when assembled on the sieve adjustment
mechanism mounting end 40.
In operation, the sieve adjustment mechanism 10 is used to adjust
the size of the openings of the sieve 110 about a plurality of size
openings by adjusting the position of a first sieve segment 110
relative to a second sieve segment 112. This is accomplished by
direct linear translation of the first sieve segment 110 as a
result of the direct connection of the rack gear 12 to the first
sieve segment 110 and without any intervening linkages or pivot
means. In other words, linear translation of the rack gear 12 moves
at least one of the first and second sieve segments 110, 112
relative to the other to adjust the size of a sieve opening of the
sieve. Referring to FIGS. 4 and 6, when the sieve adjustment
mechanism 10 is in the first position, the first sieve segment 110
is in a first position that reflects a minimized sieve opening
size. However, when the pivot handle 14 of the sieve adjustment
mechanism 10 is pivoted to the second position (FIG. 5) by the
actuator 160, the first sieve segment 110 is moved to the second
position which reflects a maximum sieve opening size. Intermediate
sized openings of the sieve 108 can be effectuated by positioning
the pivot handle 14 between the first and second positions.
In sum, owing to the direct linear translation of the rack gear 12
without the necessity of any linkage or pivoting linkages, the
present invention advantageously provides for a more accurately
controllable sieve adjustments means for controlling and adjusting
the size of openings on a sieve. That is, the rack and pinion gear
mechanism of the present invention has significantly less lost
motion or play due to the nature and tolerances of the meshing
gears of the rack and pinion gear mechanism. Further, the rack and
pinion gear mechanism of the present invention provides for true
straight line motion which is a preferred path of travel for
slats/louvers to move between open and closed positions.
Consequently, the sieve adjustment mechanism of the present
invention provides a more robust mechanism compared to conventional
sieve adjustment mechanisms and one that is less prone to
deterioration in function over time due to the simple and robust
design of the rack gear and pivot handle having a pinion gear of
the present invention.
Another advantage of the present invention is that it can be used
to replace existing pivoting handle assemblies of a conventional
sieve adjustment assembly. That is, the sieve adjustment mechanism
10 can be coupled to an existing arm 104 of conventional
sieves.
In accordance with another aspect, instead of a separate rack gear
12 and arm 104 that connects to the sieve segments of a sieve, a
rack gear 12' can be formed, and preferably integrally formed, as
part of the arm 104' that extends to the support 30 for engagement
with the pinion gear 20, as shown in FIG. 10. As such, an
additional linkage between the rack gear 12' and the arm 104',
along with its play and lost motion, can be eliminated.
In other words, the arm 104' extends between and operatively
connects e.g., first and second sieve segments, as discussed in the
above embodiment, for moving at least one of the first and second
sieve segments relative to the other to adjust the size of a sieve
opening of the sieve. Preferably, the arm 104' is configured to
move in a linear direction to effectuate movement of the first and
second sieve segments relative to each other. More preferably, the
arm 104' is connected to at least one of the first and second sieve
segments so as to be substantially transverse to a longitudinal
axis of the first and/or second sieve segments. The arm 104'
includes the rack gear 12' formed at an end of the arm 104' and
preferably integrally formed at the end of the arm 104'. The end of
the arm 104' having the rack gear 12' extends further past the
plurality of sieve segments of the sieve so as to reach and engage
a sieve adjustment mechanism 10'.
The sieve adjustment mechanism 10' includes a pinion gear 20 that
operatively connects to the rack gear 12' for moving the arm 104'
in a linear direction. The sieve adjustment mechanism 10'
operatively engages with the rack gear 12' of the arm 104' for
moving at least one of the first and second sieve segments relative
to the other. The pinion gear 20 preferably includes an integrally
formed elongated handle 14.
The sieve adjustment mechanism 10' also includes an actuator 160
connected to the pinion gear 20 for pivoting the pinion gear 20
about a first axis. Thus, in operation, the actuator 160 is
preferably assembled to the pinion gear 20 and configured to move
in a direction substantially traverse to the linear direction of
travel of the arm 104', as shown in FIG. 10.
It will be understood that changes in the details, materials,
steps, and arrangements of parts which have been described and
illustrated to explain the nature of the invention will occur to
and may be made by those skilled in the art upon a reading of this
disclosure within the principles and scope of the invention. The
foregoing description illustrates the preferred embodiments of the
invention; however, concepts, as based upon the description, may be
employed in other embodiments without departing from the scope of
the invention. Accordingly, the following claims are intended to
protect the invention broadly as well as in the specific form
shown.
* * * * *